Refactor: No more than 1 namespace declaration per file (microsoft#35373)

* Refactor: No more than 1 namespace declaration per file

* Simplify refs where possible

Author: weswigham

.eslintrc.json

@@ -54,6 +54,7 @@
         "simple-indent": "error",
         "debug-assert": "error",
         "no-keywords": "error",
+        "one-namespace-per-file": "error",
 
         // eslint-plugin-import
         "import/no-extraneous-dependencies": ["error", { "optionalDependencies": false }],

Gulpfile.js

@@ -587,15 +587,15 @@ task("generate-spec").description = "Generates a Markdown version of the Languag
 task("clean", series(parallel(cleanTasks), cleanBuilt));
 task("clean").description = "Cleans build outputs";
 
-const configureNightly = () => exec(process.execPath, ["scripts/configurePrerelease.js", "dev", "package.json", "src/compiler/core.ts"]);
+const configureNightly = () => exec(process.execPath, ["scripts/configurePrerelease.js", "dev", "package.json", "src/compiler/corePublic.ts"]);
 task("configure-nightly", series(buildScripts, configureNightly));
 task("configure-nightly").description = "Runs scripts/configurePrerelease.ts to prepare a build for nightly publishing";
 
-const configureInsiders = () => exec(process.execPath, ["scripts/configurePrerelease.js", "insiders", "package.json", "src/compiler/core.ts"]);
+const configureInsiders = () => exec(process.execPath, ["scripts/configurePrerelease.js", "insiders", "package.json", "src/compiler/corePublic.ts"]);
 task("configure-insiders", series(buildScripts, configureInsiders));
 task("configure-insiders").description = "Runs scripts/configurePrerelease.ts to prepare a build for insiders publishing";
 
-const configureExperimental = () => exec(process.execPath, ["scripts/configurePrerelease.js", "experimental", "package.json", "src/compiler/core.ts"]);
+const configureExperimental = () => exec(process.execPath, ["scripts/configurePrerelease.js", "experimental", "package.json", "src/compiler/corePublic.ts"]);
 task("configure-experimental", series(buildScripts, configureExperimental));
 task("configure-experimental").description = "Runs scripts/configurePrerelease.ts to prepare a build for experimental publishing";
 

scripts/eslint/rules/one-namespace-per-file.ts

@@ -0,0 +1,44 @@
+import { AST_NODE_TYPES, TSESTree } from "@typescript-eslint/experimental-utils";
+import { createRule } from "./utils";
+
+export = createRule({
+    name: "one-namespace-per-file",
+    meta: {
+        docs: {
+            description: `Limits each file to having at most one top-level namespace declaration`,
+            category: "Possible Errors",
+            recommended: "error",
+        },
+        messages: {
+            excessNamespaceError: `All but one of these namespaces should be moved into seperate files.`,
+        },
+        schema: [],
+        type: "problem",
+    },
+    defaultOptions: [],
+
+    create(context) {
+        const isNamespaceDeclaration = (node: TSESTree.Node): node is TSESTree.TSModuleDeclaration => node.type === AST_NODE_TYPES.TSModuleDeclaration;
+
+        const checkSourceFile = (node: TSESTree.Program) => {
+            if (context.getFilename().endsWith(".d.ts")) {
+                return;
+            }
+            const members = node.body;
+            const namespaces = members.filter(isNamespaceDeclaration);
+            if (namespaces.length <= 1) {
+                return;
+            }
+
+            namespaces.forEach(n => {
+                context.report({
+                    messageId: "excessNamespaceError", node: n
+                });
+            });
+        };
+
+        return {
+            Program: checkSourceFile,
+        };
+    },
+});

src/compiler/builder.ts

@@ -1183,165 +1183,4 @@ namespace ts {
             return Debug.assertDefined(state.program);
         }
     }
-}
-
-namespace ts {
-    export type AffectedFileResult<T> = { result: T; affected: SourceFile | Program; } | undefined;
-
-    export interface BuilderProgramHost {
-        /**
-         * return true if file names are treated with case sensitivity
-         */
-        useCaseSensitiveFileNames(): boolean;
-        /**
-         * If provided this would be used this hash instead of actual file shape text for detecting changes
-         */
-        createHash?: (data: string) => string;
-        /**
-         * When emit or emitNextAffectedFile are called without writeFile,
-         * this callback if present would be used to write files
-         */
-        writeFile?: WriteFileCallback;
-    }
-
-    /**
-     * Builder to manage the program state changes
-     */
-    export interface BuilderProgram {
-        /*@internal*/
-        getState(): ReusableBuilderProgramState;
-        /*@internal*/
-        backupState(): void;
-        /*@internal*/
-        restoreState(): void;
-        /**
-         * Returns current program
-         */
-        getProgram(): Program;
-        /**
-         * Returns current program that could be undefined if the program was released
-         */
-        /*@internal*/
-        getProgramOrUndefined(): Program | undefined;
-        /**
-         * Releases reference to the program, making all the other operations that need program to fail.
-         */
-        /*@internal*/
-        releaseProgram(): void;
-        /**
-         * Get compiler options of the program
-         */
-        getCompilerOptions(): CompilerOptions;
-        /**
-         * Get the source file in the program with file name
-         */
-        getSourceFile(fileName: string): SourceFile | undefined;
-        /**
-         * Get a list of files in the program
-         */
-        getSourceFiles(): readonly SourceFile[];
-        /**
-         * Get the diagnostics for compiler options
-         */
-        getOptionsDiagnostics(cancellationToken?: CancellationToken): readonly Diagnostic[];
-        /**
-         * Get the diagnostics that dont belong to any file
-         */
-        getGlobalDiagnostics(cancellationToken?: CancellationToken): readonly Diagnostic[];
-        /**
-         * Get the diagnostics from config file parsing
-         */
-        getConfigFileParsingDiagnostics(): readonly Diagnostic[];
-        /**
-         * Get the syntax diagnostics, for all source files if source file is not supplied
-         */
-        getSyntacticDiagnostics(sourceFile?: SourceFile, cancellationToken?: CancellationToken): readonly Diagnostic[];
-        /**
-         * Get the declaration diagnostics, for all source files if source file is not supplied
-         */
-        getDeclarationDiagnostics(sourceFile?: SourceFile, cancellationToken?: CancellationToken): readonly DiagnosticWithLocation[];
-        /**
-         * Get all the dependencies of the file
-         */
-        getAllDependencies(sourceFile: SourceFile): readonly string[];
-
-        /**
-         * Gets the semantic diagnostics from the program corresponding to this state of file (if provided) or whole program
-         * The semantic diagnostics are cached and managed here
-         * Note that it is assumed that when asked about semantic diagnostics through this API,
-         * the file has been taken out of affected files so it is safe to use cache or get from program and cache the diagnostics
-         * In case of SemanticDiagnosticsBuilderProgram if the source file is not provided,
-         * it will iterate through all the affected files, to ensure that cache stays valid and yet provide a way to get all semantic diagnostics
-         */
-        getSemanticDiagnostics(sourceFile?: SourceFile, cancellationToken?: CancellationToken): readonly Diagnostic[];
-        /**
-         * Emits the JavaScript and declaration files.
-         * When targetSource file is specified, emits the files corresponding to that source file,
-         * otherwise for the whole program.
-         * In case of EmitAndSemanticDiagnosticsBuilderProgram, when targetSourceFile is specified,
-         * it is assumed that that file is handled from affected file list. If targetSourceFile is not specified,
-         * it will only emit all the affected files instead of whole program
-         *
-         * The first of writeFile if provided, writeFile of BuilderProgramHost if provided, writeFile of compiler host
-         * in that order would be used to write the files
-         */
-        emit(targetSourceFile?: SourceFile, writeFile?: WriteFileCallback, cancellationToken?: CancellationToken, emitOnlyDtsFiles?: boolean, customTransformers?: CustomTransformers): EmitResult;
-        /**
-         * Get the current directory of the program
-         */
-        getCurrentDirectory(): string;
-    }
-
-    /**
-     * The builder that caches the semantic diagnostics for the program and handles the changed files and affected files
-     */
-    export interface SemanticDiagnosticsBuilderProgram extends BuilderProgram {
-        /**
-         * Gets the semantic diagnostics from the program for the next affected file and caches it
-         * Returns undefined if the iteration is complete
-         */
-        getSemanticDiagnosticsOfNextAffectedFile(cancellationToken?: CancellationToken, ignoreSourceFile?: (sourceFile: SourceFile) => boolean): AffectedFileResult<readonly Diagnostic[]>;
-    }
-
-    /**
-     * The builder that can handle the changes in program and iterate through changed file to emit the files
-     * The semantic diagnostics are cached per file and managed by clearing for the changed/affected files
-     */
-    export interface EmitAndSemanticDiagnosticsBuilderProgram extends SemanticDiagnosticsBuilderProgram {
-        /**
-         * Emits the next affected file's emit result (EmitResult and sourceFiles emitted) or returns undefined if iteration is complete
-         * The first of writeFile if provided, writeFile of BuilderProgramHost if provided, writeFile of compiler host
-         * in that order would be used to write the files
-         */
-        emitNextAffectedFile(writeFile?: WriteFileCallback, cancellationToken?: CancellationToken, emitOnlyDtsFiles?: boolean, customTransformers?: CustomTransformers): AffectedFileResult<EmitResult>;
-    }
-
-    /**
-     * Create the builder to manage semantic diagnostics and cache them
-     */
-    export function createSemanticDiagnosticsBuilderProgram(newProgram: Program, host: BuilderProgramHost, oldProgram?: SemanticDiagnosticsBuilderProgram, configFileParsingDiagnostics?: readonly Diagnostic[]): SemanticDiagnosticsBuilderProgram;
-    export function createSemanticDiagnosticsBuilderProgram(rootNames: readonly string[] | undefined, options: CompilerOptions | undefined, host?: CompilerHost, oldProgram?: SemanticDiagnosticsBuilderProgram, configFileParsingDiagnostics?: readonly Diagnostic[], projectReferences?: readonly ProjectReference[]): SemanticDiagnosticsBuilderProgram;
-    export function createSemanticDiagnosticsBuilderProgram(newProgramOrRootNames: Program | readonly string[] | undefined, hostOrOptions: BuilderProgramHost | CompilerOptions | undefined, oldProgramOrHost?: CompilerHost | SemanticDiagnosticsBuilderProgram, configFileParsingDiagnosticsOrOldProgram?: readonly Diagnostic[] | SemanticDiagnosticsBuilderProgram, configFileParsingDiagnostics?: readonly Diagnostic[], projectReferences?: readonly ProjectReference[]) {
-        return createBuilderProgram(BuilderProgramKind.SemanticDiagnosticsBuilderProgram, getBuilderCreationParameters(newProgramOrRootNames, hostOrOptions, oldProgramOrHost, configFileParsingDiagnosticsOrOldProgram, configFileParsingDiagnostics, projectReferences));
-    }
-
-    /**
-     * Create the builder that can handle the changes in program and iterate through changed files
-     * to emit the those files and manage semantic diagnostics cache as well
-     */
-    export function createEmitAndSemanticDiagnosticsBuilderProgram(newProgram: Program, host: BuilderProgramHost, oldProgram?: EmitAndSemanticDiagnosticsBuilderProgram, configFileParsingDiagnostics?: readonly Diagnostic[]): EmitAndSemanticDiagnosticsBuilderProgram;
-    export function createEmitAndSemanticDiagnosticsBuilderProgram(rootNames: readonly string[] | undefined, options: CompilerOptions | undefined, host?: CompilerHost, oldProgram?: EmitAndSemanticDiagnosticsBuilderProgram, configFileParsingDiagnostics?: readonly Diagnostic[], projectReferences?: readonly ProjectReference[]): EmitAndSemanticDiagnosticsBuilderProgram;
-    export function createEmitAndSemanticDiagnosticsBuilderProgram(newProgramOrRootNames: Program | readonly string[] | undefined, hostOrOptions: BuilderProgramHost | CompilerOptions | undefined, oldProgramOrHost?: CompilerHost | EmitAndSemanticDiagnosticsBuilderProgram, configFileParsingDiagnosticsOrOldProgram?: readonly Diagnostic[] | EmitAndSemanticDiagnosticsBuilderProgram, configFileParsingDiagnostics?: readonly Diagnostic[], projectReferences?: readonly ProjectReference[]) {
-        return createBuilderProgram(BuilderProgramKind.EmitAndSemanticDiagnosticsBuilderProgram, getBuilderCreationParameters(newProgramOrRootNames, hostOrOptions, oldProgramOrHost, configFileParsingDiagnosticsOrOldProgram, configFileParsingDiagnostics, projectReferences));
-    }
-
-    /**
-     * Creates a builder thats just abstraction over program and can be used with watch
-     */
-    export function createAbstractBuilder(newProgram: Program, host: BuilderProgramHost, oldProgram?: BuilderProgram, configFileParsingDiagnostics?: readonly Diagnostic[]): BuilderProgram;
-    export function createAbstractBuilder(rootNames: readonly string[] | undefined, options: CompilerOptions | undefined, host?: CompilerHost, oldProgram?: BuilderProgram, configFileParsingDiagnostics?: readonly Diagnostic[], projectReferences?: readonly ProjectReference[]): BuilderProgram;
-    export function createAbstractBuilder(newProgramOrRootNames: Program | readonly string[] | undefined, hostOrOptions: BuilderProgramHost | CompilerOptions | undefined, oldProgramOrHost?: CompilerHost | BuilderProgram, configFileParsingDiagnosticsOrOldProgram?: readonly Diagnostic[] | BuilderProgram, configFileParsingDiagnostics?: readonly Diagnostic[], projectReferences?: readonly ProjectReference[]): BuilderProgram {
-        const { newProgram, configFileParsingDiagnostics: newConfigFileParsingDiagnostics } = getBuilderCreationParameters(newProgramOrRootNames, hostOrOptions, oldProgramOrHost, configFileParsingDiagnosticsOrOldProgram, configFileParsingDiagnostics, projectReferences);
-        return createRedirectedBuilderProgram({ program: newProgram, compilerOptions: newProgram.getCompilerOptions() }, newConfigFileParsingDiagnostics);
-    }
-}
+}